Between the board and the wheels is a curved layer of fiberglass called a spring.

Designer Mitch Mulder compares the spring's flexibility to the water under a surfboard.

"The whole idea is to carve and be one with the pavement," said Mulder, 28, of North Muskegon.

He recently demonstrated the smooth ride, weaving the SoulArc down a tree-lined hill in Grand Haven.

"It's definitely a unique product. There is nothing like it out there," said Salvatore "Sam" Vilardi, 28. The Wyoming resident was the engineer for Mulder's design, finding the right materials and also the investors to bring it to market.

The duo plan to unveil their "high performance" skateboard, which will sell at a base price of $260, at the Action Sports Retail trade show in San Diego on Sept. 4-6 and the Surf Expo in Orlando, Fla., on Sept. 12-14.

Press Photo/Mark Copier"The whole idea is to carve and be one with the pavement," Mitch Mulder says.

The board is the result of a class project while Mulder attended Kendall College of Art and Design six years ago.

While his classmates were building furniture, Mulder was creating his ultimate skateboard. But after he graduated, Mulder shelved his thesis project and got a design job.

At his design firm, he met Vilardi, who revived the project by bringing in a relative to provide funding for developing prototypes. The process took about 18 months.

During that time, Mulder logged many test hours on the board.

The pair expect to sell their first 300 skateboards before arriving at the trade shows. The boards are being assembled by the Santa Ana, Calif., company Tenacore Holding Inc., which bought a 20 percent stake in SoulArc, which also is the name of the company.

The name comes from the surfing phrase "soul arch," which describes when someone is one with the wave.

SoulArc is a longboard, the longer version of the skateboard. At 38 inches long and 10 1/4 inches wide, SoulArc is about 6 to 12 inches longer than a traditional skateboard. It comes with a handle at the end to make carrying the heavier board easier.

The two envision developing a snowboard and surfboard version, along with accessories: gloves, hats, pads, shoes and clothing line.